There are membrane separation devices known, which allow the simulation of filtration processes as well as permeation processes. Often they are employed in a batch-process mode, whereby the to be tested medium after throttling of the system pressure is recirculated into an atmospheric container as retentate. The system pressure built up is almost with no exception provided by means of high pressure pumps.
Known membrane separation devices utilize flat membranes in circular or square cut forms which are employed in a two-dimensional surface plane. These known devices are employed in test cells, which arc commonly used for Membrane technical investigations such as cross flow, and pressure filtration. The test celes consist of a two part pressure housing, with the flat membrane supported between the upper and lower housing parts. The membrane itself typically rests on a filter support structure which is equipped with a flow channel, with the opening into the test cell oriented toward the membrane. The ends of flow channels are connected to a feed nozzle and concentrate draw off nozzle, respectively.
In these heretofore known test cells, the filtrate is directed away through a flow channel which) is operatively associated with the membrane. Through the feed nozzle the conglomerate material is introduced perpendicular onto the membrane, and the conglomerate material is escorted away over the concentrate draw off nozzle, also perpendicularly. To protect the membrane from wear of the feed flow impact, deflector plates are installed between the feed flow nozzle and membrane. Flow against the membrane is guided in a parallel, spiral or meandering course over the membrane.
In such known pilot test cells, the membrane surface cannot be utilized altogether satisfactorily for medium separation, up to about 35% of the membrane surface remaining unusable. Such unoptimized membrane utilization works as a disadvantage for throughput evaluation of the pilot test cell. Therefore, a very reluctant upconcentration is shown. This results in time wasted, an unnecessary superheating of the medium (without underpressure circulation), and, under certain circumstances, requires an additional cooling or tempering step.
Furthermore, it is known of typical mediums to be investigated that they are subject to transporting limitations. For example, typical mediums wherein use of such a test cell is advantageous are often viewed as dangerous goods (i.e., hazardous materials subject to transport limitations), have high organic content which may cause bacteriological contamination during the time of transportation and therefore a distinct alteration in the nature of the medium, and/or are toxic and originally located in a foreign country raising problem with border crossing. Moreover, return transport or disposal (often as hazardous waste) of the already tested medium is expensive. These complications are magnified since heretofore known testing devices typically require more than 100 Liters of the medium for the purpose of such membrane technical investigations. Such transportation and disposal difficulties could be improved Rout for the limited mobility of the test units themselves (thus limiting availability of field testing).
Further improvements of such membrane test units could thus be utilized directed to making thee units relatively more light weight, transportable i.e., mobile), and capable of faster and more reliable investigation of environmentally relevant materials.